CEPHALOPODS OF THE PHILIPPINE ISLANDS 17 



Eyes open, perforate, eyeball not covered by skin of head; sucker rings 

 smooth, toothed, or modified into hooks; shell well developed, slender, or 

 occasionally absent. Suborder Oegopsida 26 



20. Mantle stout to slender; fins terminal (marginal in Sepioteuthis) ; body 



bluntly pointed ^^ 



Mantle slender; fins subterminal, body drawn out into a long slender pomt 

 Qj. ^g^ji Uroteuthis bartschi (p. 89) 



21. Gladius broad, with rounded borders, not thickened near edge 22 



Gladius narrow, with straight edges, borders thickened and darkened . . 25 



22. Fins terminal, rhombic, occupying about half the mantle length .... 23 

 Fins marginal, occupying nearly 90 percent of mantle length. 



Sepioteuthis lessoniana (p. 77) 



23. Left ventral arm hectocotylized in male for about two-thirds of its length; 



about 7 to 10 long truncate teeth on distal half of arm suckers; teeth of 

 large suckers of club sharp and slender, irregular in size. 



Loligo edulis (p. 67) 

 About half or less of left ventral arm hectocotylized in the male .... 24 



24. More than half the length of left ventral arm hectocotylized in males; arm 



suckers with large blunt teeth nearly all around ring; large suckers of 

 club with a few sharp teeth; suckers of median rows of club not more 

 than twice the diameter of marginal suckers . Loligo duvauceli (p. 71) 

 Less than half the length of left ventral arm hectocotyUzed in males; arm 

 suckers with short truncate teeth on distal half; large suckers of club 

 with about 15 low pointed teeth of which about 2 to 4 on the distal 

 border are on a raised base and are very long and clawhke; suckers of 

 median rows of club about twice the diameter of marginal suckers. 



Loligo species A (p. 74) 



25 Left ventral arm of male hectocotylized; large club suckers with 20 to 22 

 sharp curved teeth; two to eight suckers on lobe of buccal membrane; 



large species Doryteuthis singhalensis (p. 81) 



Both ventral arms of male hectocotylized, the left longer and broader than 

 the right; tips of both ventral arms devoid of suckers, smooth; large club 

 suckers with 11 or 12 sharp slender teeth, longer and separated on distal 

 side; one to six suckers on lobe of buccal membrane; small species. 



Doryteuthis reesi (p. 84) 



26. Mantle articulates with head in neck region and on each side of funnel by 



means of grooves and ridges ^^ 



Mantle is permanently fused with head and funnel 37 



27. Hooks present on both arms and tentacles 28 



Hooks present on arms or tentacles but not on both, or absent 31 



28 Light organs on ventral surface of head forming five distinct rows .... 29 

 Light organs on ventral surface of head forming about nine distmct rows. 



Abralia andamanica (p. 99) 



29 An indistinct light organ on ink sac; fin width index 89-9^-100; mantle 



width index 33-47; right ventral arm hectocotylized in male; suckers m 



two rows on end of arms Abralia armata (p. 92) 



No light organ on ink sac; left(?) ventral arm hectocotylized in male; suck- 

 ers in four rows on end of arms; species medium size 30 



30 Three distinct rows of photophores on ventral arms with no, or only one or 



two supplementary photophores between the rows near base of arms. No 

 solitary large white photophores within funnel groove near base of first 

 nuchal fold Abralia lucens (p. 105) 



